Flaviviruses and alphaviruses are positive sense RNA viruses and are important human and/or animal pathogens that can cause acute virus infections with severe diseases and/or death. Flaviviruses include members of families Flaviviridae including Dengue Virus (DENV), Murray Valley Encephalitis Virus (MVEV), Saint Louis Encephalitis Virus (SLEV), West Nile virus (WNV), Japanese Encephalitides Virus (JEV), Yellow Fever Virus (YFV) and Tick-Borne Encephalitis Virus (TBEV) and Hepciviridae including Hepatitis C Virus (HCV) and Pestiviruses including Bovine Diarrhea virus (BVDV). Alphaviruses include Venezuela Equine Encephalitides Virus (VEEV), Eastern Equine Encephalitis Virus (EEEV), Western Equine Encephalitides virus (WEEV) and Ross River Virus (RRV). For most arbovirus listed above, there is no effective vaccine or therapeutics currently available. There are no alphavirus vaccines currently available. The need to develop antiviral drugs is urgent for developing control measures and treating these diseases.
Vast amounts of research have accrued over the years related to developing treatments against viral diseases to inhibit and kill viral infections. Some of this research has resulted in agents approved for clinical use. Nevertheless, efforts continue at an ever-increasing rate in view of the extreme difficulty in uncovering promising antiviral agents.